In this study, high performance composite electrolyte membranes were prepared from polyether ether ketone polymeric material. An initial sulfonation reaction improved the membrane hydrophilicity and its water absorbability and thus enhanced the ionic conductivity in electrochemical cells. Protonic conductivity was improved from 10⁻⁴ to 10⁻² S cm⁻¹ with an increasing sulfonation time from 72 to 175 h. The effects of blending nano SiO₂ into the composite membranes were devoted to improve thermal and mechanical properties, as well as methanol permeability. Methanol permeability was reduced to 3.1 × 10⁻⁷ cm² s⁻¹. Finally, a further improvement in ionic conductivity was carried out by a supercritical carbon dioxide treatment under 20 MPa at 40°C for 30 min with an optimum SiO₂ blend ratio of 10 wt-%. The plasticizing effect by the Lewis acid-base interaction between CO₂ and electron donor species on polymer chains decreased the glass transition and melting temperatures. The results show that sulfonated composite membranes blended with SiO₂ and using a supercritical carbon dioxide treatment exhibit a lower glass transition temperature, higher ionic conductivity, lower methanol permeability, good thermal stability, and strong mechanical properties. Ionic conductivity was improved to 1.55 × 10⁻² S cm⁻¹. The ion exchange capacity and the degree of sulfonation were also investigated.

The effects of various oxygen flows on indium gallium zinc oxide (IGZO) based thin-film transistors (TFTs) with different channel width sizes have been investigated. The IGZO nano-films exhibited amorphous phase while the bandgap energy and sheet resistance increased with increasing oxygen flow rate. The electrical characteristics were evaluated with different sizes in channel width using fixed channel length. The distributions in terms of threshold voltage and current on–off level along the different channel width sizes have been discussed thoroughly. The minimum distribution of threshold voltage was observed at an oxygen flow rate of 1 sccm. The TFT electrical properties have been achieved, using an oxygen flow rate of 1 sccm with 500 µm channel width, the threshold voltage, ratio of on-current to off-current, sub-threshold swing voltage and field effect mobility to be 0.54 V, 10⁶, 0.15 V/decade and 12.3 cm²/V·s, respectively. On the other hand, a larger channel width of 2000 µm could further improve the ratio of on-current to off-current and sub-threshold swing voltage to 10⁷ and 0.11 V/decade. The optimized combination of oxygen flow and channel width showed improved electrical characteristics for TFT applications.

This paper presents new photovoltaic solar cells with Cu₂ZnSnSe₄/CH₃NH₃PbI₃(MAPbI₃)/ZnS/IZO/Ag nanostructures on bi-layer Mo/FTO (fluorine-doped tin oxide) glasssubstrates. The hole-transporting layer, active absorber layer, electron-transporting layer, transparent-conductive oxide layer, and top electrode-metal contact layer, were made of Cu₂ZnSnSe₄, MAPbI₃ perovskite, zincsulfide, indium-doped zinc oxide, and silver, respectively. The active absorber MAPbI₃ perovskite film was deposited on Cu₂ZnSnSe₄ hole-transporting layer that has been annealed at different temperatures. TheseCu₂ZnSnSe₄ filmsexhibitedthe morphology with increased crystal grain sizesand reduced pinholes, following the increased annealing temperature. When the perovskitefilm thickness was designed at 700 nm, the Cu₂ZnSnSe₄ hole-transporting layer was 160 nm, and the IZO (indium-zinc oxide) at 100 nm, and annealed at 650 °C, the experimental results showed significant improvements in the solar cell characteristics. The open-circuit voltage was increased to 1.1 V, the short-circuit current was improved to 20.8 mA/cm², and the device fill factor was elevated to 76.3%. In addition, the device power-conversion efficiency has been improved to 17.4%. The output power P_max was as good as 1.74 mW and the device series-resistance was 17.1 Ω.